Sunan Ibn Majah, Chapter: The Chapters of Establishing the Prayer and the Sunnah Regarding Them

"The Messenger of Allah (saw) said: 'At night Satan ties a rope in which there are three knots to the nape of the neck of anyone of you. If he wakes up and remembers Allah, one knot is untied. If he performs ablution, another knot is untied, and if he gets up to pray, all the knots are untied, so he wakes up energetic and cheerful, he has already earned something good. But if he does not do that, he wakes up bad-tempered, having earned nothing good." Sahih